1. Field of the Invention
The present invention relates to a display system and a method of converting a sync signal thereof, and more particularly, to a display system which can alternatively select a video signal of one of a first video signal standard and a second video signal standard, which have different sync signal standards, to output according to a selection of a user and a method of converting a sync signal thereof.
2. Description of the Related Art
Recently, a digital set top box has been increasingly used for connecting the Internet and for watching a digital television. In particular, the digital set top box is connected to a display apparatus such as television, a computer monitor, etc. and thus provides a user with convenient services by transmitting/receiving signals through an external satellite broadcasting or an Internet connection.
The set top box, as shown in FIG. 1, comprises a tuner 114 receiving an encoded broadcasting signal through an antenna 112; a signal processor 116 processing the broadcasting signal input from the tuner 114; and an analog RGB output part 118 and a Digital Video Interface (DVI) output part 120, which output the broadcasting signal processed in the signal processor 116 to a display apparatus (not shown).
Herein, the signal processor 116 decodes the encoded broadcasting signal, converts the decoded broadcasting signal into an analog RGB data, and outputs the analog RGB data to the analog RGB output part 118, or outputs a decoded broadcasting signal to the DVI output part 120.
A schematic description of a displaying process of a broadcasting signal using the conventional set top box 200 is as follows.
The broadcasting signal received through the antenna 112 is processed using a channel tuning process by the tuner 114 to select a desired station. The broadcasting signal input by the tuner 114 is processed by the signal processor 116 and then is output by the output parts 118 and 120 after being properly formatted for the analog RGB or the DVI.
In the conventional set top box 200, an output signal standard including the analog RGB output and the DVI output of the signal processor 116 complies with either the Video Electrics Standards Association (VESA) standard or the EIA/CEA 861B standard.
As a display apparatus connected to the set top box 200, a monitor supports the VESA standard and a television supports the EIA/CEA 861B standard, in general.
Therefore, an output video signal of the set top box 200 is set to output only for the monitor supporting the VESA standard or for the television supporting the EIA/CEA 861B standard.
In other words, if the display apparatus connected to the conventional set top box does not correspond to the video signal format output from the set top box, an image shown on the display apparatus becomes shifted or fuzzy.